Method of manufacturing a semiconductor device

ABSTRACT

A method of manufacturing a semiconductor device includes forming a dopant layer including a dopant composition over a substrate. A resist layer including a resist composition is formed over the dopant layer. A dopant is diffused from the dopant composition in the dopant layer into the resist layer; and a pattern is formed in the resist layer.

BACKGROUND

As consumer devices have gotten smaller and smaller in response toconsumer demand, the individual components of these devices havenecessarily decreased in size as well. Semiconductor devices, which makeup a major component of devices such as mobile phones, computer tablets,and the like, have been pressured to become smaller and smaller, with acorresponding pressure on the individual devices (e.g., transistors,resistors, capacitors, etc.) within the semiconductor devices to also bereduced in size.

One enabling technology that is used in the manufacturing processes ofsemiconductor devices is the use of photolithographic materials. Suchmaterials are applied to a surface of a layer to be patterned and thenexposed to an energy that has itself been patterned. Such an exposuremodifies the chemical and physical properties of the exposed regions ofthe photosensitive material. This modification, along with the lack ofmodification in regions of the photosensitive material that were notexposed, can be exploited to remove one region without removing theother, or vice-verse.

However, as the size of individual devices has decreased, processwindows for photolithographic processing has become tighter and tighter.As such, advances in the field of photolithographic processing arenecessary to maintain the ability to scale down the devices, and furtherimprovements are needed in order to meet the desired design criteriasuch that the march towards smaller and smaller components may bemaintained.

As the semiconductor industry has progressed into nanometer technologyprocess nodes in pursuit of higher device density, higher performance,and lower costs, there have been challenges in reducing semiconductorfeature size.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIGS. 1A and 1B illustrate process flows of manufacturing asemiconductor device according to embodiments of the disclosure.

FIGS. 2A and 2B show process stages of a sequential operation accordingto embodiments of the disclosure.

FIGS. 3A and 3B show process stages of a sequential operation accordingto embodiments of the disclosure.

FIG. 4 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 5A and 5B show process stages of a sequential operation accordingto embodiments of the disclosure.

FIG. 6 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 7 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 8 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 9A and 9B show process stages of a sequential operation accordingto an embodiment of the disclosure.

FIGS. 10A and 10B show process stages of a sequential operationaccording to an embodiment of the disclosure.

FIGS. 11A and 11B show process stages of a sequential operationaccording to an embodiment of the disclosure.

FIG. 12 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 13A and 13B show process stages of a sequential operationaccording to an embodiment of the disclosure.

FIG. 14 illustrates examples of photoacid generators according toembodiments of the disclosure.

FIG. 15 illustrates examples of quenchers according to embodiments ofthe disclosure.

FIG. 16 illustrates examples of photobase generators according toembodiments of the disclosure.

FIG. 17 illustrates examples of crosslinkers according to embodiments ofthe disclosure.

FIG. 18 illustrates examples of non-ionic surfactants according toembodiments of the disclosure.

FIG. 19 illustrates examples of ionic surfactants according toembodiments of the disclosure.

FIG. 20 illustrates examples of EO-PO type surfactants according toembodiments of the disclosure.

FIG. 21 illustrates examples of high boiling point solvents according toembodiments of the disclosure.

FIG. 22A shows organometallic precursors according to embodiments of thedisclosure. FIG. 22B shows a reaction the organometallic precursorsundergo when exposed to actinic radiation. FIG. 22C shows examples oforganometallic precursors according to embodiments of the disclosure.

FIG. 23 illustrates a deposition apparatus according to embodiments ofthe disclosure.

FIGS. 24A and 24B show process stages of a sequential operationaccording to embodiments of the disclosure.

FIGS. 25A and 25B show process stages of a sequential operationaccording to embodiments of the disclosure.

FIG. 26 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 27A and 27B show process stages of a sequential operationaccording to embodiments of the disclosure.

FIG. 28 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 29 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 30 shows a process stage of a sequential operation according to anembodiment of the disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof the disclosure. Specific embodiments or examples of components andarrangements are described below to simplify the present disclosure.These are, of course, merely examples and are not intended to belimiting. For example, dimensions of elements are not limited to thedisclosed range or values, but may depend upon process conditions and/ordesired properties of the device. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact. Variousfeatures may be arbitrarily drawn in different scales for simplicity andclarity.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The device may be otherwise oriented (rotated 90 degrees orat other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. In addition, the term“made of” may mean either “comprising” or “consisting of.”

Extreme ultraviolet lithography has been developed for use in nanometertechnology process nodes, such as below 40 nm process nodes. C, N, Oatoms in the polymers of organic photoresists are weak in EUV photonabsorption. It has been found that certain metals have higher EUV photonabsorption. To use the higher EUV photon absorption of metals, metallicresist have been developed. However, it is desirable to improve metallicresist lithographic performance by improving the line width roughness(LWR) of the resist pattern, the peeling properties of the resist, andreducing the number of defects. It is desirable to reduce LWR to lessthan 5.0 nm, and to reduce the exposure dose of the photoresist to lessthan 70 mj. In some embodiments, the lithographic properties of metallicresists are improved by doping the metallic resist with a dopant. Insome embodiments, the dopant is one or more selected from the groupconsisting of a photoacid generator, a quencher, a photobase generator,an organic acid, an inorganic acid, an organic base, an inorganic base,a crosslinker, a surfactant, a solvent having a boiling point greaterthan 100° C., water, or a chelate.

FIG. 1A illustrates a process flow 100 of manufacturing a semiconductordevice according to embodiments of the disclosure. A dopant layer 20 iscoated on a surface of a target layer 60 to be patterned or a substrate10 in operation S110, as shown in FIG. 2A. The dopant layer 20 includesa dopant composition including a dopant. In some embodiments, a firstbaking operation is performed in operation S120 to drive off solvents inthe dopant layer composition. In some embodiments, the dopant layer 20is heated at a temperature of ranging from about 40° C. to about 120° C.for about 10 seconds to about 10 minutes.

A resist composition is coated on a surface of dopant layer 20 inoperation S130, in some embodiments, to form a resist layer 15, as shownin FIG. 2A. In some embodiments, the resist layer is a photoresistlayer. In some embodiments, the resist composition is a metallic resistcomposition and the resist layer 15 is a metallic resist layer. In someembodiments, the metallic resist composition includes one or moreorganometallic compounds. Then the resist layer 15 undergoes a second(or pre-exposure) baking operation S140 to diffuse dopants in the dopantlayer 20, as shown in FIG. 3A in some embodiments, to form a dopedresist layer 15 a, as shown in FIG. 4. In some embodiments, the dopantlayer 20 and the resist layer 15 are heated at a temperature rangingfrom about 40° C. to about 250° C. to diffuse the dopant throughoutresist layer 15. In some embodiments, the dopant is uniformlydistributed throughout the doped resist layer 15 a.

FIG. 1B illustrates a process flow 100′ of manufacturing a semiconductordevice according to embodiments of the disclosure. A resist compositionis coated on a surface of a target layer 60 to be patterned or asubstrate 10 in operation S130, as shown in FIG. 2B, to form a resistlayer 15. In some embodiments, the resist layer 15 is a photoresistlayer. In some embodiments, the resist composition is a metallic resistcomposition and the resist layer 15 is a metallic resist layer. In someembodiments, the metallic resist composition includes one or moreorganometallic compounds. In some embodiments, a first baking of theresist layer 15 is performed in operation S120. In some embodiments, theresist layer is heated at a temperature of ranging from about 40° C. toabout 120° C. for about 10 seconds to about 10 minutes to cure theresist layer or to drive off solvents.

A dopant layer 20 is formed on a surface of resist layer 15 in operationS130, in some embodiments, as shown in FIG. 2B. The dopant layer 20includes a dopant composition including a dopant. Then the dopant layer20 and the resist layer 15 undergoes a second (or pre-exposure) bakingoperation S140 to diffuse dopants in the dopant layer 20, as shown inFIG. 3B in some embodiments, to form a doped resist layer 15 a, as shownin FIG. 4. In some embodiments, the dopant layer 20 and the resist layer15 are heated at a temperature ranging from about 40° C. to about 250°C. to diffuse the dopant throughout resist layer 15. In someembodiments, the dopant is uniformly distributed throughout the dopedresist layer 15 a. In some embodiments, the dopant in the dopant layer20 is not completely distributed in the resist layer. Thus, a portion ofthe dopant layer 20 remains after the pre-exposure baking operation S140in some embodiments. In some embodiments, the pre-exposure bake alsodrives off solvents in the dopant layer 20.

After the pre-exposure baking operation S140 of the photoresist layer 15and dopant layer 20, the doped photoresist layer 15 a is selectivelyexposed to actinic radiation 45/97 (see FIGS. 5A and 5B) in operationS150. In some embodiments, the photoresist layer 15 is selectivelyexposed to ultraviolet radiation. In some embodiments, the radiation iselectromagnetic radiation, such as g-line (wavelength of about 436 nm),i-line (wavelength of about 365 nm), ultraviolet radiation, deepultraviolet radiation, extreme ultraviolet, electron beams, or the like.In some embodiments, the radiation source is selected from the groupconsisting of a mercury vapor lamp, xenon lamp, carbon arc lamp, a KrFexcimer laser light (wavelength of 248 nm), an ArF excimer laser light(wavelength of 193 nm), an F₂ excimer laser light (wavelength of 157nm), or a CO₂ laser-excited Sn plasma (extreme ultraviolet, wavelengthof 13.5 nm).

As shown in FIG. 5A, the exposure radiation 45 passes through aphotomask 30 before irradiating the photoresist layer 15 in someembodiments. In some embodiments, the photomask has a pattern to bereplicated in the doped photoresist layer 15 a. The pattern is formed byan opaque pattern 35 on the photomask substrate 40, in some embodiments.The opaque pattern 35 may be formed by a material opaque to ultravioletradiation, such as chromium, while the photomask substrate 40 is formedof a material that is transparent to ultraviolet radiation, such asfused quartz.

In some embodiments, the selective exposure of the doped photoresistlayer 15 a to form exposed regions 50 and unexposed regions 52 isperformed using extreme ultraviolet lithography. In an extremeultraviolet lithography operation a reflective photomask 65 is used toform the patterned exposure light in some embodiments, as shown in FIG.5B. The reflective photomask 65 includes a low thermal expansion glasssubstrate 70, on which a reflective multilayer 75 of Si and Mo isformed. A capping layer 80 and absorber layer 85 are formed on thereflective multilayer 75. A rear conductive layer 90 is formed on theback side of the low thermal expansion glass substrate 70. In extremeultraviolet lithography, extreme ultraviolet radiation 95 is directedtowards the reflective photomask 65 at an incident angle of about 6°. Aportion 97 of the extreme ultraviolet radiation is reflected by theSi/Mo multilayer 75 towards the photoresist coated substrate 10, whilethe portion of the extreme ultraviolet radiation incident upon theabsorber layer 85 is absorbed by the photomask. In some embodiments,additional optics, including mirrors, are between the reflectivephotomask 65 and the photoresist coated substrate.

The region of the doped photoresist layer exposed to radiation 50undergoes a chemical reaction thereby changing its solubility in asubsequently applied developer relative to the region of the dopedphotoresist layer not exposed to radiation 52. In some embodiments, theportion of the doped photoresist layer exposed to radiation 50 undergoesa crosslinking reaction.

Next, the doped photoresist layer 15 a undergoes a third baking (orpost-exposure bake (PEB)) in operation S160. In some embodiments, thedoped photoresist layer 15 a is heated at a temperature ranging fromabout 50° C. to about 160° C. for about 20 seconds to about 120 seconds.The post-exposure baking may be used to assist in the generating,dispersing, and reacting of the acid/base/free radical generated fromthe impingement of the radiation 45/97 upon the doped photoresist layer15 a during the exposure. Such assistance helps to create or enhancechemical reactions, which generate chemical differences between theexposed region 50 and the unexposed region 52 within the photoresistlayer.

The selectively exposed doped photoresist layer is subsequentlydeveloped by applying a developer to the selectively exposed dopedphotoresist layer in operation S170. As shown in FIG. 6, a developer 57is supplied from a dispenser 62 to the doped photoresist layer 15 a. Insome embodiments, the unexposed region 52 of the photoresist layer isremoved by the developer 57 forming a pattern of openings 55 in thedoped photoresist layer 15 a to expose the substrate 10, as shown inFIG. 7.

In some embodiments, the pattern of openings 55 in the doped photoresistlayer 15 a is extended into the substrate 10 to create a pattern ofopenings 55′ in the substrate 10, thereby transferring the pattern inthe doped photoresist layer 15 a into the substrate 10, as shown in FIG.8. The pattern is extended into the substrate by etching, using one ormore suitable etchants. In some embodiments, the etching operationremoves portions of the dopant layer still remaining if the dopant isnot completely diffused into the resist layer. The photoresist layerpattern 50 is at least partially removed during the etching operation insome embodiments. In other embodiments, the photoresist layer pattern 50and any remaining portions of the dopant layer 20 under the photoresistlayer pattern 55 are removed after etching the substrate 10 by using asuitable photoresist stripper solvent or by a photoresist ashingoperation.

In some embodiments, the substrate 10 includes a single crystallinesemiconductor layer on at least it surface portion. The substrate 10 mayinclude a single crystalline semiconductor material such as, but notlimited to Si, Ge, SiGe, GaAs, InSb, GaP, GaSb, InAlAs, InGaAs, GaSbP,GaAsSb and InP. In some embodiments, the substrate 10 is a silicon layerof an SOI (silicon-on insulator) substrate. In certain embodiments, thesubstrate 10 is made of crystalline Si.

The substrate 10 may include in its surface region, one or more bufferlayers (not shown). The buffer layers can serve to gradually change thelattice constant from that of the substrate to that of subsequentlyformed source/drain regions. The buffer layers may be formed fromepitaxially grown single crystalline semiconductor materials such as,but not limited to Si, Ge, GeSn, SiGe, GaAs, InSb, GaP, GaSb, InAlAs,InGaAs, GaSbP, GaAsSb, GaN, GaP, and InP. In an embodiment, the silicongermanium (SiGe) buffer layer is epitaxially grown on the siliconsubstrate 10. The germanium concentration of the SiGe buffer layers mayincrease from 30 atomic % for the bottom-most buffer layer to 70 atomic% for the top-most buffer layer.

In some embodiments, the substrate 10 includes one or more layers of atleast one metal, metal alloy, and metal nitride sulfide/oxide/silicidehaving the formula MX_(a), where M is a metal and X is N, S, Se, O, Si,and a is from about 0.4 to about 2.5. In some embodiments, the substrate10 includes titanium, aluminum, cobalt, ruthenium, titanium nitride,tungsten nitride, tantalum nitride, and combinations thereof.

In some embodiments, the substrate 10 includes a dielectric having atleast a silicon or metal oxide or nitride of the formula MX_(b), where Mis a metal or Si, X is N or O, and b ranges from about 0.4 to about 2.5.In some embodiments, the substrate 10 includes silicon dioxide, siliconnitride, aluminum oxide, hafnium oxide, lanthanum oxide, andcombinations thereof.

In some embodiments, a dopant composition 20′ is applied to the surfaceof a substrate 10 as a liquid. In some embodiments, the dopant is mixedwith a solvent and then applied to the surface of the substrate. Inother embodiments, the dopant is a liquid. In some embodiments, thedopant composition 20′ is applied by spin coating on the dopantcomposition 20′ as shown in FIG. 9A. A resist composition 15′ issubsequently applied to the surface of the dopant layer 20 as a liquid.In some embodiments, the resist composition 15′ is spin coated over thedopant layer 20, as shown in FIG. 9B. In some embodiments, the spincoated dopant layer 20 is baked at a temperature ranging from about 40°C. to about 120° C. for about 10 seconds to about 10 minutes before theresist composition 15′ is applied to the surface of the dopant layer 20.In other embodiments, the resist composition 15′ is applied to thesurface of the dopant layer 20 before heating the dopant layer, and theresist layer 15 and the dopant layer 20 are heated together at atemperature ranging from about 40° C. to about 250° C. for about 10seconds to about 10 minutes to diffuse the dopant into the resist layer15 and cure and dry the resist layer 15.

In some embodiments, the resist composition 15′ is applied to thesurface of a substrate 10 as a liquid. In some embodiments, the resistcomposition 15′ is applied by spin coating on the substrate 10, as shownin FIG. 10A. The dopant composition 20′ is subsequently applied to thesurface of the resist layer 15 as a liquid. In some embodiments, thedopant is mixed with a solvent and then applied to the surface of theresist layer. In other embodiments, the dopant is a liquid. In someembodiments, the dopant composition 20′ is spin coated over the resistlayer 15, as shown in FIG. 10B. In some embodiments, the spin coatedresist layer 15 is baked at a temperature ranging from about 40° C. toabout 120° C. for about 10 seconds to about 10 minutes before the dopantcomposition 20′ is applied to the surface of the resist layer 15. Inother embodiments, the dopant composition 20′ is applied to the surfaceof the resist layer 15 before heating the resist layer, and the resistlayer 15 and the dopant layer 20 are heated together at a temperatureranging from about 40° C. to about 250° C. for about 10 seconds to about10 minutes to diffuse the dopant into the resist layer 15 and cure anddry the resist layer 15.

In some embodiments, the dopant composition 20′ is applied to thesurface of a substrate 10 by a vapor phase deposition technique, asshown in FIG. 11A. A resist composition 15′ is subsequently applied tothe surface of the dopant layer 20 by a vapor phase depositiontechnique, as shown in FIG. 11B. In some embodiments, the vapordeposition technique is selected from the group consisting of chemicalvapor deposition (CVD), physical vapor deposition (PVD), and atomiclayer deposition (ALD). In some embodiments, the dopant layer 20 isbaked at a temperature ranging from about 40° C. to about 120° C. forabout 10 seconds to about 10 minutes before the resist composition 15′is applied to the surface of the dopant layer 20. In other embodiments,the resist composition 15′ is applied to the surface of the dopant layer20 before heating the dopant layer, and the resist layer 15 and thedopant layer 20 are heated together at a temperature ranging from about40° C. to about 250° C. for about 10 seconds to about 10 minutes todiffuse the dopant into the resist layer 15.

In some embodiments, the dopant composition 20′ and the resistcomposition 15′ are deposited at substantially the same time using avapor phase deposition technique, as shown in FIG. 12. In such a case, aseparate diffusion operation is not performed in some embodiments.

In some embodiments, the resist composition 15′ is applied to thesurface of a substrate 10 by a vapor phase deposition technique, asshown in FIG. 13A. A dopant composition 20′ is subsequently applied tothe surface of the resist layer 15 by a vapor phase depositiontechnique, such as CVD, PVD, or ALD, as shown in FIG. 13B. In someembodiments, the resist layer 15 is baked at a temperature ranging fromabout 40° C. to about 120° C. for about 10 seconds to about 10 minutesbefore the dopant composition 20′ is applied to the surface of theresist layer 15. In other embodiments, the dopant composition 20′ isapplied to the surface of the resist layer 15 before heating the resistlayer, and the resist layer 15 and the dopant layer 20 are heatedtogether at a temperature ranging from about 40° C. to about 250° C. forabout 10 seconds to about 10 minutes to diffuse the dopant into theresist layer 15.

In some embodiments, a combination of liquid deposition and vapor phasedeposition techniques are used to form the dopant layer 20 and theresist layer 15. For example, in some embodiments, the dopant layer 20is formed by a spin coating technique and then the resist layer 15 isformed by a vapor phase deposition technique. In other embodiments, thedopant layer 20 is formed by a vapor phase deposition technique and thenthe resist layer 15 is formed by a spin coating technique. In otherembodiments, the resist layer 15 is formed by a spin coating techniqueand then the dopant layer 20 is formed vapor phase deposition technique.In other embodiments, the resist layer 15 is formed by a vapor phasedeposition technique and then the dopant layer 20 is formed by a spincoating technique.

The dopant composition includes the dopant composition comprises one ormore of a photoacid generator, a quencher, a photobase generator, anorganic acid, an inorganic acid, an organic base, an inorganic base, acrosslinker, a surfactant, a solvent having a boiling point greater than100° C., water, or a chelate. In some embodiments, the dopant is mixedwith a solvent and then applied to the surface of the substrate 10 orthe resist layer 15.

FIG. 14 illustrates examples of photoacid generators (PAGs) according toembodiments of the disclosure. The photoacid generators illustrated inFIG. 14 are compounds including a cation and an anion. In someembodiments, the PAGs include halogenated triazines, onium salts,diazonium salts, aromatic diazonium salts, phosphonium salts, sulfoniumsalts, iodonium salts, imide sulfonate, oxime sulfonate, diazodisulfone,disulfone, o-nitrobenzylsulfonate, sulfonated esters, halogenatedsulfonyloxy dicarboximides, diazodisulfones, α-cyanooxyamine-sulfonates,imidesulfonates, ketodiazosulfones, sulfonyldiazoesters,1,2-di(arylsulfonyl)hydrazines, nitrobenzyl esters, and the s-triazinederivatives, combinations of these, or the like.

Some specific examples of photoacid generators includeα-(trifluoromethylsulfonyloxy)-bicyclo[2.2.1]hept-5-ene-2,3-dicarb-o-ximide(MDT), N-hydroxy-naphthalimide (DDSN), benzoin tosylate,t-butylphenyl-α-(p-toluenesulfonyloxy)-acetate andt-butyl-α-(p-toluenesulfonyloxy)-acetate, triarylsulfonium anddiaryliodonium hexafluoroantimonates and hexafluoroarsenates,trifluoromethanesulfonates, iodonium perfluorooctanesulfonate,N-camphorsulfonyloxynaphthalimide,N-pentafluorophenylsulfonyloxynaphthalimide, ionic iodonium sulfonatessuch as diaryl iodonium (alkyl or aryl)sulfonate andbis-(di-t-butylphenyl)iodonium camphanylsulfonate,perfluoroalkanesulfonates such as perfluoropentanesulfonate,perfluorooctanesulfonate, perfluoromethanesulfonate, aryl (e.g., phenylor benzyl)triflates such as triphenylsulfonium triflate orbis-(t-butylphenyl)iodonium triflate; pyrogallol derivatives (e.g.,trimesylate of pyrogallol), trifluoromethanesulfonate esters ofhydroxyimides, α,α′-bis-sulfonyl-diazomethanes, sulfonate esters ofnitro-substituted benzyl alcohols, naphthoquinone-4-diazides, alkyldisulfones, or the like.

In some embodiments, the PAG is mixed with a solvent and then themixture is applied to the surface of the substrate 10 or the resistlayer 15. When the PAG doped photoresist layer 15 a is exposed toactinic radiation, the PAG absorbs the radiation and generates an acid.The generated acid assists the photochemical reaction occurring in thedoped photoresist layer. In some embodiments, a concentration of the PAGin the doped photoresist layer ranges from about 0.1 wt. % to about 20wt. % based on the weight of the PAG and the resist composition. At PAGconcentrations below the disclosed range there may not be a sufficientamount of the PAG to provide a measurable improvement in the resistparameters or performance. At PAG concentrations above the disclosedrange there may not be a significant additional improvement in theresist parameters or performance.

Metallic resists used in EUV and e-beam applications typically do notinclude photoacid generators (PAGs). In the present disclosure, PAGs areintroduced into resist layer 15 to provide improved pattern resolutionand improved line width roughness (LWR). The inclusion of PAGs in theresist layer 15 enable the use of lower exposure doses during thephotoresist exposure operation and provide increased yield ofsemiconductor devices.

In some embodiments, the dopant is a quencher. In some embodiments, thequencher is an amine, such as a second lower aliphatic amine, a tertiarylower aliphatic amine, or the like. Specific examples of amines includetrimethylamine, diethylamine, triethylamine, di-n-propylamine,tri-n-propylamine, tripentylamine, diethanolamine, and triethanolamine,alkanolamine, combinations thereof, or the like. FIG. 15 illustratesexamples of quenchers according to embodiments of the disclosure.

In some embodiments, the quencher is mixed with a solvent and then themixture is applied to the surface of the substrate 10 or the resistlayer 15. In some embodiments, an amount of the quencher in the dopedphotoresist layer ranges from about 0.1 wt. % to about 20 wt. % based onthe weight of the quencher and the resist composition. At quencherconcentrations below the disclosed range there may not be a sufficientamount of the quencher to provide a measurable improvement in the resistparameters or performance. At quencher concentrations above thedisclosed range there may not be a significant additional improvement inthe resist parameters or performance.

In some embodiments, the dopant is a photobase generator (PBG). In someembodiments, the PBG is a quaternary ammonium dithiocarbamate, an aaminoketones, an oxime-urethane containing molecule such asdibenzophenoneoxime hexamethylene diurethan, ammonium tetraorganylboratesalts, and N-(2-nitrobenzyloxycarbonyl)cyclic amines. FIG. 16illustrates examples of photobase generators according to embodiments ofthe disclosure.

In some embodiments, the PBG is mixed with a solvent and then themixture is applied to the surface of the substrate 10 or the resistlayer 15. In some embodiments, a concentration of the PBG in the dopedphotoresist layer ranges from about 0.1 wt. % to about 20 wt. % based onthe weight of the PBG and the resist composition. At PBG concentrationsbelow the disclosed range there may not be a sufficient amount of thePBG to provide a measurable improvement in the resist parameters orperformance. At PBG concentrations above the disclosed range there maynot be a significant additional improvement in the resist parameters orperformance.

Metallic resists used in EUV and e-beam applications typically do notinclude a quencher or a PBG. In the present disclosure, a quencher or aPBG is introduced into resist layer 15 to provide improved patternresolution and improved line width roughness (LWR). The inclusion of aquencher or a PBG in the resist layer 15 enable the use of lowerexposure doses during the photoresist exposure operation and provideincreased yield of semiconductor devices.

FIG. 17 illustrates examples of crosslinkers according to embodiments ofthe disclosure. R1 in the examples of FIG. 17 is a polymer or a C1-C20hydrocarbon group. In some embodiments, the C1-C20 hydrocarbon group isan aliphatic or aromatic group. In some embodiments, the C1-C20hydrocarbon group is aryl, alkyl, or alkenyl group. In some embodiments,the C1-C20 is substituted with one or more of a halogen, a carbonylgroup, a hydroxyl group, a carboxyl group, and an ester group, achalcogen, a thionyl group, or a thiol group. In FIG. 17, m and n rangefrom 1 to 6. In some embodiments, the crosslinker is activated byheating the doped photoresist layer at temperature ranging from about20° C. (room temperature) to about 300° C. In some embodiments, anamount of the crosslinker in the doped photoresist layer ranges fromabout 0.1 wt. % to about 20 wt. % based on the weight of the crosslinkerand the resist composition. At crosslinker concentrations below thedisclosed range there may not be a sufficient amount of the crosslinkerto provide a measurable improvement in the resist parameters orperformance. At crosslinker concentrations above the disclosed rangethere may not be a significant additional improvement in the resistparameters or performance.

In some embodiments, the dopant composition includes a surfactant. FIG.18 illustrates examples of non-ionic surfactants according toembodiments of the disclosure. In some embodiments, the non-ionicsurfactants have a structure of A-X or A-X-A-X, where A is an aliphaticor aromatic, unbranched or branched, cyclic or non-cyclic C2-C100 carbongroup. The C2-C100 group may an alkyl group, an alkenyl group, a phenylgroup, or two or more fused phenyl groups, each of which may besubstituted with oxygen or a halogen. X is an alkyl group substitutedwith one or more polar functional groups selected from the groupconsisting of —OH, ═O, —C(═O)SH, —C(═O)OH, —C(═O)NH, —SO₂OH, —SO₂SH,—SOH; or is one or more linking groups selected from the groupconsisting of —SO₂—, —CO—, —CN—, —SO—, —CON—, —NH—, —SO₃NH—, SO₂NH—,—S—, —P—, —P(O₂)—, —C(═O)OR—, —O—, and —N—. FIG. 19 illustrates examplesof ionic surfactants according to embodiments of the disclosure.

FIG. 20 illustrates examples of ethylene oxide (EO)-propylene oxide (PO)type surfactants according to embodiments of the disclosure. In someembodiments, R is a C1-C20 hydrocarbon group. In some embodiments, theC1-C20 hydrocarbon group is an aliphatic or aromatic group. In someembodiments, the C1-C20 hydrocarbon group is aryl, alkyl, or alkenylgroup. In some embodiments, the C1-C20 is substituted with one or moreof a halogen, a carbonyl group, a hydroxyl group, a carboxyl group, andan ester group, a chalcogen, a thionyl group, or a thiol group. In FIG.20, n ranges from 1 to 6.

In some embodiments, the chelate is one or more ofethylenediaminetetraacetic acid (EDTA), ethylenediamine-N,N′-disuccinicacid (EDDS), diethyl enetriaminepentaacetic acid (DTPA), polyasparticacid, trans-1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acidmonohydrate, ethylenediamine, or the like.

In some embodiments, a concentration of the surfactant or chelate in thedoped photoresist layer ranges from about 0.1 wt. % to about 20 wt. %based on the weight of the surfactant or chelate and the resistcomposition. At surfactant or chelate concentrations below the disclosedrange there may not be a sufficient amount of the crosslinker to providea measurable improvement in the resist parameters or performance. Atsurfactant or chelate concentrations above the disclosed range there maynot be a significant additional improvement in the resist parameters orperformance.

The high boiling point solvent has a boiling point greater than 100° C.In some embodiments, the high boiling point solvent includes one or moreof cyclohexyl acetate, dipropylene glycol dimethyl ether, propyleneglycol diacetate, dipropylene glycol methyl propylene ether,di(propylene glycol) methyl ether acetate, 1,4-diacetoxybutane,1,3-butanediol diacetate, 1,6-diacetoxyhexane, tripropylene glycolmethyl ether, 1,3-propanediol, propylene glycol, 1,3-butanediol,propylene glycol butyl ether, dipropylene glycol monomethyl ether,diethylene glycol monoethyl ether, di(propylene glycol) butyl ether, ortri(propylene glycol) butyl ether. FIG. 21 illustrates examples of highboiling point solvents according to embodiments of the disclosure. Insome embodiments, the resist layer 15 is doped with the high boilingpoint solvent by applying the high boiling point solvent to the resistlayer 15 as a liquid, vapor, or a mist.

In some embodiments, a concentration of the high boiling point solventin the doped photoresist layer ranges from about 0.1 wt. % to about 20wt. % based on the weight of the high boiling point solvent and theresist composition. At high boiling point solvent concentrations belowthe disclosed range there may not be a sufficient amount of the highboiling point solvent to provide a measurable improvement in the resistparameters or performance. At high boiling point solvent concentrationsabove the disclosed range there may not be a significant additionalimprovement in the resist parameters or performance.

In some embodiments, the organic or inorganic acid has a pK_(a) of lessthan 7. The acid dissociation constant, pK_(a), is the logarithmicconstant of the acid dissociation constant K_(a). K_(a) is aquantitative measure of the strength of an acid in solution. K_(a) isthe equilibrium constant for the dissociation of a generic acidaccording to the equation HA+H₂O↔A⁻+H₃O⁺, where HA dissociates into itsconjugate base, A⁻, and a hydrogen ion which combines with a watermolecule to form a hydronium ion. The dissociation constant can beexpressed as a ratio of the equilibrium concentrations:

$K_{a} = {\frac{\lbrack A^{-} \rbrack\lbrack {H_{3}O^{+}} \rbrack}{\lbrack{HA}\rbrack\lbrack {H_{2}O} \rbrack}.}$

In most cases, the amount of water is constant and the equation can besimplified to HA↔A⁻+H⁺, and

$K_{a} = {\frac{\lbrack A^{-} \rbrack\lbrack H^{+} \rbrack}{ \{ {HA}  \rbrack}.}$

The logarithmic constant, pK_(a) is related to K_(a) by the equationpK_(a)=−log₁₀(K_(a)). The lower the value of pK_(a) the stronger theacid. Conversely, the higher the value of pK_(a) the stronger the base.

In some embodiments, suitable organic acids for dopant compositioninclude an organic acid selected from the group consisting of formicacid, acetic acid, ethanedioic acid, 2-hydroxyethanoic acid, oxoethanoicacid, propanoic acid, propanedioic acid, 2-hydroxypropanoic acid,butanoic acid, 2-hydroxybutanedioic acid, butanedioic acid,3-oxobutanoic acid, pentanoic acid, hexanoic acid, heptanoic acid,caprylic acid, citric acid, uric acid, trifluoromethanesulfonic acid,benzenesulfonic acid, ethanesulfonic acid, methanesulfonic acid, maleicacid, carbonic acid, hydroxylamine-o-sulfonic acid, formamidinesulfinicacid, methylsulfamic acid, sulfoacetic acid,1,1,2,2-tetrafluoroethanesulfonic acid, 1,3-propanedisulfonic acid,nonafluorobutane-1-sulfonic acid, 5-sulfosalicylic acid, trichloroaceticacid, and combinations thereof. In some embodiments, suitable inorganicacids for the dopant composition include one or more of nitric acid,sulfuric acid, hydrofluoric acid, hydrochloric acid, phosphoric acid,hydrobromic acid, hydroiodic acid, perchloric acid, and combinationsthereof.

In some embodiments, the organic or inorganic base has a pK_(a) ofgreater than 7. In some embodiments, suitable bases for the dopantcomposition include an alkanolamine, a triazole, or an ammoniumcompound. In some embodiments, suitable bases include an organic baseselected from the group consisting of monoethanolamine,monoisopropanolamine, 2-amino-2-methyl-1-propanol, 1H-benzotriazole,1,2,4-triazole, 1,8-diazabicycloundec-7-ene, ammonium carbamate,tetramethylammonium hydroxide, tetraethylammonium hydroxide,tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide, andNHR₂ and NH₂R, where R is a substituted or unsubstituted, aliphatic oraromatic C1-C15 group, and combinations thereof. In some embodiments,suitable inorganic bases for the dopant composition include a baseselected from the group consisting of ammonium hydroxide, ammoniumsulfamate, potassium hydroxide, sodium hydroxide, and combinationsthereof.

In some embodiments, a concentration of the acid or base in the dopedphotoresist layer ranges from about 0.1 wt. % to about 20 wt. % based onthe weight of the acid or base and the resist composition. At acid orbase concentrations below the disclosed range there may not be asufficient amount of the acid or base to provide a measurableimprovement in the resist parameters or performance. At acid or baseconcentrations above the disclosed range there may not be a significantadditional improvement in the resist parameters or performance.

In some embodiments, the resist layer 15 is doped with water by applyingthe water to the resist layer 15 as a liquid, vapor, or a mist. In someembodiments, a concentration of water in the doped photoresist layerranges from about 0.1 wt. % to about 20 wt. % based on the weight of thewater and the resist composition. At water concentrations below thedisclosed range there may not be a sufficient amount of the water toprovide a measurable improvement in the resist parameters orperformance. At water concentrations above the disclosed range there maynot be a significant additional improvement in the resist parameters orperformance.

In some embodiments, the dopant is dissolved into or mixed with one ormore solvents selected from the group consisting of propylene glycolmethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME),1-ethoxy-2-propanol (PGEE), γ-butyrolactone (GBL), cyclohexanone (CHN),ethyl lactate (EL), methanol, ethanol, propanol, n-butanol, acetone,dimethylformamide (DMF), isopropanol (IPA), tetrahydrofuran (THF),methyl isobutyl carbinol (MIBC), n-butyl acetate (nBA), 2-heptanone(MAK), formic acid, acetic acid, propanoic acid, and butanoic acid.

In some embodiments, the dopant composition does not include a polymer.In some embodiments, the dopant composition does not include an organicpolymer. In some embodiments, the dopant composition does not include anorganic polymer with a nitrogen-containing moiety. Thus, in someembodiments, there are no organic polymers or organic polymers with anitrogen-containing moiety in the dopant layer 20.

The photoresist layer 15 is a photosensitive layer that is patterned byexposure to actinic radiation. Typically, the chemical properties of thephotoresist regions struck by incident radiation change in a manner thatdepends on the type of photoresist used. Photoresist layers 15 arepositive tone resists or negative tone resists. A positive tone resistrefers to a photoresist material that when exposed to actinic radiation(e.g., UV light) becomes soluble in a developer, while the region of thephotoresist that is non-exposed (or exposed less) is insoluble in thedeveloper. A negative tone resist, on the other hand, refers to aphotoresist material that when exposed to actinic radiation becomesinsoluble in the developer, while the region of the photoresist that isnon-exposed (or exposed less) is soluble in the developer. The region ofa negative tone resist that becomes insoluble upon exposure to radiationmay become insoluble due to a cross-linking reaction caused by theexposure to radiation.

In some embodiments of the present disclosure, a negative tonephotoresist is exposed to actinic radiation. The exposed portions of thenegative tone photoresist undergo crosslinking because of the exposureto actinic radiation, and during development the unexposed,non-crosslinked portions of the photoresist are removed by the developerleaving the exposed regions of the photoresist remaining on thesubstrate.

In some embodiments, the photoresist layer 15 is a negative tonemetallic photoresist that undergoes a cross-linking reaction uponexposure to the radiation.

In some embodiments, the photoresist layer 15 is made of a metallicphotoresist composition, including a first compound or a first precursorand a second compound or a second precursor combined in a vapor state.The first precursor or first compound is an organometallic having aformula: M_(a)R_(b)X_(c), as shown in FIG. 22A, where M is at least oneof Sn, Bi, Sb, In, Te, Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As,Y, La, Ce, or Lu; and R is a substituted or unsubstituted alkyl,alkenyl, or carboxylate group. In some embodiments, M is selected fromthe group consisting of Sn, Bi, Sb, In, Te, and combinations thereof. Insome embodiments, R is a C3-C6 alkyl, alkenyl, or carboxylate. In someembodiments, R is selected from the group consisting of propyl,isopropyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, isopentyl,sec-pentyl, tert-pentyl, hexyl, iso-hexyl, sec-hexyl, tert-hexyl, andcombinations thereof. X is a ligand, ion, or other moiety, which isreactive with the second compound or second precursor; and 1≤a≤2, b≥1,c≥1, and b+c≤5 in some embodiments. In some embodiments, the alkyl,alkenyl, or carboxylate group is substituted with one or more fluorogroups. In some embodiments, the organometallic precursor is a dimer, asshown in FIG. 22A, where each monomer unit is linked by an amine group.Each monomer has a formula: M_(a)R_(b)X_(c), as defined above.

In some embodiments, R is alkyl, such as C_(n)H_(2n+1) where n≥3. Insome embodiments, R is fluorinated, e.g., having the formulaC_(n)F_(x)H_(((2n+1)−x)). In some embodiments, R has at least onebeta-hydrogen or beta-fluorine. In some embodiments, R is selected fromthe group consisting of i-propyl, n-propyl, t-butyl, i-butyl, n-butyl,sec-butyl, n-pentyl, i-pentyl, t-pentyl, and sec-pentyl, andcombinations thereof.

In some embodiments, X is any moiety readily displaced by the secondcompound or second precursor to generate an M-OH moiety, such as amoiety selected from the group consisting of amines, includingdialkylamino and monalkylamino; alkoxy; carboxylates, halogens, andsulfonates. In some embodiments, the sulfonate group is substituted withone or more amine groups. In some embodiments, the halide is one or moreselected from the group consisting of F, Cl, Br, and I. In someembodiments, the sulfonate group includes a substituted or unsubstitutedC1-C3 group.

In some embodiments, the first organometallic compound or firstorganometallic precursor includes a metallic core M⁺ with ligands Lattached to the metallic core M⁺, as shown in FIG. 22B. In someembodiments, the metallic core M⁺ is a metal oxide. The ligands Linclude C3-C12 aliphatic or aromatic groups in some embodiments. Thealiphatic or aromatic groups may be unbranched or branched with cyclic,or noncyclic saturated pendant groups containing 1-9 carbons, includingalkyl groups, alkenyl groups, and phenyl groups. The branched groups maybe further substituted with oxygen or halogen. In some embodiments, theC3-C12 aliphatic or aromatic groups include heterocyclic groups. In someembodiments, the C3-C12 aliphatic or aromatic groups are attached to themetal by an ether or ester linkage. In some embodiments, the C3-C12aliphatic or aromatic groups include nitrite and sulfonate substituents.

In some embodiments, the organometallic precursor or organometalliccompound include a sec-hexyl tris(dimethylamino) tin, t-hexyltris(dimethylamino) tin, i-hexyl tris(dimethylamino) tin, n-hexyltris(dimethylamino) tin, sec-pentyl tris(dimethylamino) tin, t-pentyltris(dimethylamino) tin, i-pentyl tris(dimethylamino) tin, n-pentyltris(dimethylamino) tin, sec-butyl tris(dimethylamino) tin, t-butyltris(dimethylamino) tin, i-butyl tris(dimethylamino) tin, n-butyltris(dimethylamino) tin, sec-butyl tris(dimethylamino) tin,i-propyl(tris)dimethylamino tin, n-propyl tris(diethylamino) tin, andanalogous alkyl(tris)(t-butoxy) tin compounds, including sec-hexyltris(t-butoxy) tin, t-hexyl tris(t-butoxy) tin, i-hexyl tris(t-butoxy)tin, n-hexyl tris(t-butoxy) tin, sec-pentyl tris(t-butoxy), t-pentyltris(t-butoxy) tin, i-pentyl tris(t-butoxy) tin, n-pentyl tris(t-butoxy)tin, t-butyl tris(t-butoxy) tin, i-butyl tris(butoxy) tin, n-butyltris(butoxy) tin, sec-butyl tris(butoxy) tin,i-propyl(tris)dimethylamino tin, or n-propyl tris(butoxy) tin. In someembodiments, the organometallic precursors or organometallic compoundsare fluorinated. In some embodiments, the organometallic precursors orcompounds have a boiling point less than about 200° C.

In some embodiments, the first compound or first precursor includes oneor more unsaturated bonds that can be coordinated with a functionalgroup, such as a hydroxyl group, on the surface of the substrate or anintervening underlayer to improve adhesion of the photoresist layer tothe substrate or underlayer.

In some embodiments, the second precursor or second compound is at leastone of an amine, a borane, a phosphine, or water. In some embodiments,the amine has a formula N_(p)H_(n)X_(m), where 0≤n≤3, 0≤m≤3, n+m=3 whenp is 1, and n+m=4 when p is 2, and each X is independently a halogenselected from the group consisting of F, Cl, Br, and I. In someembodiments, the borane has a formula B_(p)H_(n)X_(m), where 0≤n≤3,0≤m≤3, n+m=3 when p is 1, and n+m=4 when p is 2, and each X isindependently a halogen selected from the group consisting of F, Cl, Br,and I. In some embodiments, the phosphine has a formula P_(p)H_(n)X_(m),where 0≤n≤3, 0≤m≤3, n+m=3, when p is 1, or n+m=4 when p is 2, and each Xis independently a halogen selected from the group consisting of F, Cl,Br, and I.

FIG. 22B shows metallic precursors undergoing a reaction as a result ofexposure to actinic radiation in some embodiments. As a result ofexposure to the actinic radiation, ligand groups L are split off fromthe metallic core M⁺ of the metallic precursors, and two or moremetallic precursor cores bond with each other.

FIG. 22C shows examples of organometallic precursors according toembodiments of the disclosure. In FIG. 22C, Bz is a benzene group.

In some embodiments, the operation S130 of depositing a photoresistcomposition is performed by a vapor phase deposition operation. In someembodiments, the vapor phase deposition operation includes atomic layerdeposition (ALD) and chemical vapor deposition (CVD). In someembodiments, the ALD includes plasma-enhanced atomic layer deposition(PE-ALD); the CVD includes plasma-enhanced chemical vapor deposition(PE-CVD), metal-organic chemical vapor deposition (MO-CVD), atmosphericpressure chemical vapor deposition (AP-CVD), and low pressure chemicalvapor deposition (LP-CVD).

A resist layer deposition apparatus 200 according to some embodiments ofthe disclosure is shown in FIG. 23. In some embodiments, the depositionapparatus 200 is an ALD or CVD apparatus. The deposition apparatus 200includes a vacuum chamber 205. A substrate support stage 210 in thevacuum chamber 205 supports a substrate 10, such as silicon wafer. Insome embodiments, the substrate support stage 210 includes a heater. Afirst precursor or compound gas supply 220 and carrier/purge gas supply225 are connected to an inlet 230 in the chamber via a gas line 235, anda second precursor or compound gas supply 240 and carrier/purge gassupply 225 are connected to another inlet 230′ in the chamber viaanother gas line 235′ in some embodiments. The chamber is evacuated, andexcess reactants and reaction byproducts are removed by a vacuum pump245 via an outlet 250 and exhaust line 255. In some embodiments, theflow rate or pulses of precursor gases and carrier/purge gases,evacuation of excess reactants and reaction byproducts, pressure insidethe vacuum chamber 205, and temperature of the vacuum chamber 205 orwafer support stage 210 are controlled by a controller 260 configured tocontrol each of these parameters.

Depositing a photoresist layer includes combining the first compound orfirst precursor and the second compound or second precursor in a vaporstate to form the photoresist composition in some embodiments. In someembodiments, the first compound or first precursor and the secondcompound or second precursor of the photoresist composition areintroduced into the deposition chamber 205 (CVD chamber) at about thesame time via the inlets 230, 230′. In some embodiments, the firstcompound or first precursor and second compound or second precursor areintroduced into the deposition chamber 205 (ALD chamber) in analternating manner via the inlets 230, 230′, i.e.—first one compound orprecursor then a second compound or precursor, and then subsequentlyalternately repeating the introduction of the one compound or precursorfollowed by the second compound or precursor.

In some embodiments, the deposition chamber temperature ranges fromabout 30° C. to about 400° C. during the deposition operation, andbetween about 50° C. to about 250° C. in other embodiments. In someembodiments, the pressure in the deposition chamber ranges from about 5mTorr to about 100 Torr during the deposition operation, and betweenabout 100 mTorr to about 10 Torr in other embodiments. In someembodiments, the plasma power is less than about 1000 W. In someembodiments, the plasma power ranges from about 100 W to about 900 W. Insome embodiments, the flow rate of the first compound or precursor andthe second compound or precursor ranges from about 100 sccm to about1000 sccm. In some embodiments, the ratio of the flow of theorganometallic compound precursor to the second compound or precursorranges from about 1:1 to about 1:5. At operating parameters outside theabove-recited ranges, unsatisfactory photoresist layers result in someembodiments. In some embodiments, the photoresist layer formation occursin a single chamber (a one-pot layer formation).

In a CVD process according to some embodiments of the disclosure, two ormore gas streams, in separate inlet paths 230, 235 and 230′, 235′, of anorganometallic precursor and a second precursor are introduced to thedeposition chamber 205 of a CVD apparatus, where they mix and react inthe gas phase, to form a reaction product. The streams are introducedusing separate injection inlets 230, 230′ or a dual-plenum showerhead insome embodiments. The deposition apparatus is configured so that thestreams of organometallic precursor and second precursor are mixed inthe chamber, allowing the organometallic precursor and second precursorto react to form a reaction product. Without limiting the mechanism,function, or utility of the disclosure, it is believed that the productfrom the vapor-phase reaction becomes heavier in molecular weight, andis then condensed or otherwise deposited onto the substrate 10.

In some embodiments, an ALD process is used to deposit the photoresistlayer. During ALD, a layer is grown on a substrate 10 by exposing thesurface of the substrate to alternate gaseous compounds (or precursors).In contrast to CVD, the precursors are introduced as a series ofsequential, non-overlapping pulses. In each of these pulses, theprecursor molecules react with the surface in a self-limiting way, sothat the reaction terminates once all the reactive sites on the surfaceare consumed. Consequently, the maximum amount of material deposited onthe surface after a single exposure to all of the precursors (aso-called ALD cycle) is determined by the nature of theprecursor-surface interaction.

In an embodiment of an ALD process, an organometallic precursor ispulsed to deliver the metal-containing precursor to the substrate 10surface in a first half reaction. In some embodiments, theorganometallic precursor reacts with a suitable underlying species (forexample OH or NH functionality on the surface of the substrate) to forma new self-saturating surface. Excess unused reactants and the reactionby-products are removed, by an evacuation-pump down using a vacuum pump245 and/or by a flowing an inert purge gas in some embodiments. Then, asecond precursor, such as ammonia (NH₃), is pulsed to the depositionchamber in some embodiments. The NH₃ reacts with the organometallicprecursor on the substrate to obtain a reaction product photoresist onthe substrate surface. The second precursor also forms self-saturatingbonds with the underlying reactive species to provide anotherself-limiting and saturating second half reaction. A second purge isperformed to remove unused reactants and the reaction by-products insome embodiments. Pulses of the first precursor and second precursor arealternated with intervening purge operations until a desired thicknessof the photoresist layer is achieved.

The resist layer deposition apparatus 200 illustrated in FIG. 23 is alsoused to form the dopant layer 20 in some embodiments.

In some embodiments, the photoresist layer 15 is formed to a thicknessof about 5 nm to about 50 nm, and to a thickness of about 10 nm to about30 nm in other embodiments. A person of ordinary skill in the art willrecognize that additional ranges of thicknesses within the explicitranges above are contemplated and are within the present disclosure. Thethickness can be evaluated using non-contact methods of x-rayreflectivity and/or ellipsometry based on the optical properties of thephotoresist layers. In some embodiments, each photoresist layerthickness is relatively uniform to facilitate processing. In someembodiments, the variation in thickness of the deposited photoresistlayer varies by no more than ±25% from the average thickness, in otherembodiments each photoresist layer thickness varies by no more than ±10%from the average photoresist layer thickness. In some embodiments, suchas high uniformity depositions on larger substrates, the evaluation ofthe photoresist layer uniformity may be evaluated with a 1 centimeteredge exclusion, i.e., the layer uniformity is not evaluated for portionsof the coating within 1 centimeter of the edge. A person of ordinaryskill in the art will recognize that additional ranges within theexplicit ranges above are contemplated and are within the presentdisclosure.

In some embodiments, the first and second compounds or precursors aredelivered into the deposition chamber 205 with a carrier gas. Thecarrier gas, a purge gas, a deposition gas, or other process gas maycontain nitrogen, hydrogen, argon, neon, helium, or combinationsthereof.

In some embodiments, the organometallic compound includes tin (Sn),antimony (Sb), bismuth (Bi), indium (In), and/or tellurium (Te) as themetal component, however, the disclosure is not limited to these metals.In other embodiments, additional suitable metals include titanium (Ti),zirconium (Zr), hafnium (Hf), vanadium (V), cobalt (Co), molybdenum(Mo), tungsten (W), aluminum (Al), gallium (Ga), silicon (Si), germanium(Ge), phosphorus (P), arsenic (As), yttrium (Y), lanthanum (La), cerium(Ce), lutetium (Lu), or combinations thereof. The additional metals canbe as alternatives to or in addition to the Sn, Sb, Bi, In, and/or Te.

The particular metal used may significantly influence the absorption ofradiation. Therefore, the metal component can be selected based on thedesired radiation and absorption cross section. Tin, antimony, bismuth,tellurium, and indium provide strong absorption of extreme ultravioletlight at 13.5 nm. Hafnium provides good absorption of electron beam andextreme UV radiation. Metal compositions including titanium, vanadium,molybdenum, or tungsten have strong absorption at longer wavelengths, toprovide, for example, sensitivity to 248 nm wavelength ultravioletlight.

In some embodiments, the resist layer 15 is formed by mixing theorganometallic compound in a solvent to form a resist composition anddispensing the resist composition onto the substrate 10. To aid in themixing and dispensing of the photoresist, the solvent is chosen at leastin part based upon the materials chosen for the metallic resist. In someembodiments, the solvent is chosen such that the organometallic isevenly dissolved into the solvent and dispensed upon the layer to bepatterned.

In some embodiments, the resist solvent is an organic solvent, andincludes any suitable solvent such as propylene glycol methyl etheracetate (PGMEA), propylene glycol monomethyl ether (PGME),1-ethoxy-2-propanol (PGEE), γ-butyrolactone (GBL), cyclohexanone (CHN),ethyl lactate (EL), methanol, ethanol, propanol, n-butanol, acetone,dimethylformamide (DMF), isopropanol (IPA), tetrahydrofuran (THF),methyl isobutyl carbinol (MIBC), n-butyl acetate (nBA), 2-heptanone(MAK), formic acid, acetic acid, propanoic acid, butanoic acid, or thelike.

As one of ordinary skill in the art will recognize, the materials listedand described above as examples of materials that may be used for thesolvent component of the photoresist are merely illustrative and are notintended to limit the embodiments. Rather, any suitable material thatdissolves the metallic photoresist material may be used to help mix andapply the photoresist. All such materials are fully intended to beincluded within the scope of the embodiments.

The dopant composition and photoresist composition are applied onto thelayer to be patterned, as shown in FIGS. 2A and 2B, such as thesubstrate 10 to form the dopant layer 20 and the photoresist layer 15.In some embodiments, the dopant composition and the photoresistcomposition are applied using a process such as a spin-on coatingprocess, a dip coating method, an air-knife coating method, a curtaincoating method, a wire-bar coating method, a gravure coating method, alamination method, an extrusion coating method, CVD, ALD, PVD,combinations of these, or the like. In some embodiments, the photoresistlayer 15 thickness ranges from about 10 nm to about 300 nm. In someembodiments, the dopant layer 20 thickness ranges from about 5 nm toabout 100 nm, and ranges from about 10 nm to about 50 nm in otherembodiments.

After the photoresist layer 15 and dopant layer 20 have been applied tothe substrate 10 and first and second baking operations (S120, S140) areperformed as necessary, as discussed herein (see FIGS. 1A, 1B, 3A, and3B), the doped photoresist layer 15 a is selectively exposed to form anexposed region 50 and an unexposed region 52, as discussed herein, andshown in FIGS. 5A and 5B. In some embodiments, the exposure to radiationis carried out by placing the doped photoresist coated substrate in aphotolithography tool. The photolithography tool includes a photomask30, 65 optics, an exposure radiation source to provide the radiation 45,97 for exposure, and a movable stage for supporting and moving thesubstrate under the exposure radiation.

The selectively exposed doped photoresist layer 15 a is subsequentlydeveloped, as shown in FIG. 6. In some embodiments of the disclosure,the developer composition, includes: a first solvent having Hansensolubility parameters of 18>δ_(d)>3, 7>δ_(p)>1, and 7>δ_(h)>1; anorganic acid having an acid dissociation constant, pKa, of −11<pKa<4;and a Lewis acid, wherein the organic acid and the Lewis acid aredifferent. In some embodiments, the developer includes a base having apK_(a) of 40>pK_(a)>9.5.

The units of the Hansen solubility parameters are (Joules/cm³)^(1/2) or,equivalently, MPa^(1/2) and are based on the idea that one molecule isdefined as being like another if it bonds to itself in a similar way.δ_(d) is the energy from dispersion forces between molecules. δ_(p) isthe energy from dipolar intermolecular force between the molecules.δ_(h) is the energy from hydrogen bonds between molecules. The threeparameters, δ_(d), δ_(p), and δ_(h), can be considered as coordinatesfor a point in three dimensions, known as the Hansen space. The nearertwo molecules are in Hansen space, the more likely they are to dissolveinto each other.

In some embodiments, the concentration of the first solvent ranges fromabout 60 wt. % to about 99 wt. % based on a total weight of thedeveloper composition. In some embodiments, the concentration of thefirst solvent is greater than 60 wt. %. In other embodiments, theconcentration of the concentration of the first solvent ranges fromabout 70 wt. % to about 90 wt. % based on a total weight of thedeveloper composition. In some embodiments, the first solvent is one ormore of n-butyl acetate, methyl n-amyl ketone, hexane, heptane, and amylacetate.

In some embodiments, the organic acid is one or more of ethanedioicacid, methanoic acid, 2-hydroxypropanoic acid, 2-hydroxybutanedioicacid, citric acid, uric acid, trifluoromethanesulfonic acid,benzenesulfonic acid, ethanesulfonic acid, methanesulfonic acid, andmaleic acid. In some embodiments, the concentration of the organic acidis about 0.001 wt. % to about 30 wt. % based on a total weight of thedeveloper composition.

In some embodiments, suitable bases for the photoresist developercomposition 57 include an alkanolamine, a triazole, or an ammoniumcompound. In some embodiments, suitable bases include an organic baseselected from the group consisting of monoethanolamine,monoisopropanolamine, 2-amino-2-methyl-1-propanol, 1H-benzotriazole,1,2,4-triazole, 1,8-diazabicycloundec-7-ene, tetramethylammoniumhydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide,and tetrabutylammonium hydroxide, and combinations thereof; or inorganicbases selected from the group consisting of ammonium hydroxide, ammoniumsulfamate, ammonium carbamate, and combinations thereof or inorganicbases selected from the group consisting of ammonium hydroxide, ammoniumsulfamate, ammonium carbamate, and combinations thereof. In someembodiments, the base is selected from the group consisting ofmonoisopropanolamine, 2-amino-2-methyl-1-propanol, 1H-benzotriazole,1,2,4-triazole, 1,8-diazabicycloundec-7-ene, and combinations thereof.In some embodiments, the concentration of the base is about 0.001 wt. %to about 30 wt. % based on a total weight of the developer composition.

In some embodiments, the concentration of the Lewis acid is about 0.1wt. % to about 15 wt. % based on a total weight of the developercomposition, and in other embodiments, the concentration of the Lewisacid is about 1 wt. % to about 5 wt. % based on a total weight of thedeveloper composition.

In some embodiments, the developer composition includes a second solventhaving Hansen solubility parameters of 25>δ_(d)>13, 25>δ_(p)>3, and30>δ_(h)>4, and the first solvent and the second solvent are differentsolvents. In some embodiments, the concentration of the second solventranges from about 0.1 wt. % to less than about 40 wt. % based on a totalweight of the developer composition. In some embodiments, the secondsolvent is one or more of propylene glycol methyl ether, propyleneglycol ethyl ether, γ-butyrolactone, cyclohexanone, ethyl lactate,methanol, ethanol, propanol, n-butanol, acetone, dimethyl formamide,acetonitrile, isopropanol, tetrahydrofuran, or acetic acid.

In some embodiments, the developer composition includes about 0.001 wt.% to about 30 wt. % of a chelate based on the total it of the developercomposition. In other embodiments, the developer composition includesabout 0.1 wt. % to about 20 wt. % of the chelate based on the totalweight of the developer composition. In some embodiments, the chelate isone or more of ethylenediaminetetraacetic acid (EDTA),ethylenediamine-N,N′-disuccinic acid (EDDS),diethylenetriaminepentaacetic acid (DTPA), polyaspartic acid,trans-1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid monohydrate,ethylenediamine, or the like.

In some embodiments, the developer composition includes water orethylene glycol at a concentration of about 0.001 wt. % to about 30 wt.% based on a total weight of the developer composition.

In some embodiments, the photoresist developer composition includes asurfactant in a concentration range of from about 0.001 wt. % to aboutless than 5 wt. % based on a total weight of the developer compositionto increase the solubility and reduce the surface tension on thesubstrate. In other embodiments, the concentration of the surfactantranges from about 0.01 wt. % to about 1 wt. % based on the total weightof the developer composition.

At concentrations of the developer composition components outside thedisclosed ranges, developer composition performance and developmentefficiency may be reduced, leading to increased photoresist residue andscum in the photoresist pattern, and increased line width roughness andline edge roughness.

In some embodiments, the developer 57 is applied to the photoresistlayer 15 using a spin-on process. In the spin-on process, the developer57 is applied to the photoresist layer 15 from above the photoresistlayer 15 while the photoresist coated substrate is rotated, as shown inFIG. 6. In some embodiments, the developer 57 is supplied at a rate ofbetween about 5 ml/min and about 800 ml/min, while the photoresistcoated substrate 10 is rotated at a speed of between about 100 rpm andabout 2000 rpm. In some embodiments, the developer is at a temperatureof between about 20° C. and about 75° C. during the developmentoperation. The development operation continues for between about 10seconds to about 10 minutes in some embodiments.

While the spin-on operation is one suitable method for developing thephotoresist layer 15 after exposure, it is intended to be illustrativeand is not intended to limit the embodiment. Rather, any suitabledevelopment operations, including dip processes, puddle processes, andspray-on methods, may alternatively be used. All such developmentoperations are included within the scope of the embodiments.

During the development process, the developer composition 57 dissolvesthe photoresist regions 52 not exposed to radiation (i.e.—notcrosslinked), exposing the surface of the substrate 10, as shown in FIG.7, and leaving behind well-defined exposed photoresist regions 50,having improved definition than provided by conventional negative tonephotoresist photolithography.

After the developing operation S170, remaining developer is removed fromthe patterned photoresist covered substrate. The remaining developer isremoved using a spin-dry process in some embodiments, although anysuitable removal technique may be used. After the photoresist layer 15is developed, and the remaining developer is removed, additionalprocessing is performed while the patterned photoresist layer 50 is inplace. For example, an etching operation, using dry or wet etching, isperformed in some embodiments, to transfer the pattern of thephotoresist layer 50 to the underlying substrate 10, forming recesses55′ as shown in FIG. 8. The substrate 10 has a different etch resistancethan the photoresist layer 15. In some embodiments, the etchant is moreselective to the substrate 10 than the photoresist layer 15.

In some embodiments, a layer to be patterned (target layer) 60 isdisposed over the substrate prior to forming the dopant layer 20 and thephotoresist layer 15, as shown in FIGS. 24A and 24B. Baking operationsS120 are performed, as necessary to dry and cure the dopant layer 20 andphotoresist layer 15, as discussed herein in reference to FIGS. 1A, 1B,2A, and 2B. In some embodiments, the target layer 60 is a metallizationlayer or a dielectric layer, such as a passivation layer, disposed overa metallization layer. In embodiments where the target layer 60 is ametallization layer, the target layer 60 is formed of a conductivematerial using metallization processes, and metal deposition techniques,including chemical vapor deposition, atomic layer deposition, andphysical vapor deposition (sputtering). Likewise, if the target layer 60is a dielectric layer, the target layer 60 is formed by dielectric layerformation techniques, including thermal oxidation, CVD, ALD, and PVD.

As shown in FIGS. 25A and 25B, a pre-exposure bake (S140) is performedto diffuse the dopant into the photoresist layer 15, as discussed hereinin reference to FIGS. 3A and 3B, to form the doped photoresist layer 15a, as shown in FIG. 26, and as discussed herein in reference to FIG. 4(see FIGS. 1A and 1B).

The doped photoresist layer 15 a is subsequently selectively exposed toactinic radiation 45, 97 to form exposed regions 50 and unexposedregions 52 in the doped photoresist layer, as shown in FIGS. 27A and27B, and described herein in relation to FIGS. 5A and 5B. As explainedherein the photoresist is a negative photoresist, wherein crosslinkingoccurs in the exposed regions 50 in some embodiments.

As shown in FIG. 28, the selectively exposed photoresist layer 50, 52 isdeveloped by dispensing developer 57 from a dispenser 62 to form apattern of photoresist openings 55, as shown in FIG. 29. The developmentoperation is similar to that explained with reference to FIGS. 6 and 7,herein.

Then as shown in FIG. 30, the pattern 55 in the photoresist layer 15 istransferred to the target layer 60 using an etching operation and thephotoresist layer is removed, as explained with reference to FIG. 8 toform pattern 55″ in the target layer 60.

Other embodiments include other operations before, during, or after theoperations described above. In some embodiments, the disclosed methodsinclude forming fin field effect transistor (FinFET) structures. In someembodiments, a plurality of active fins are formed on the semiconductorsubstrate. Such embodiments, further include etching the substratethrough the openings of a patterned hard mask to form trenches in thesubstrate; filling the trenches with a dielectric material; performing achemical mechanical polishing (CMP) process to form shallow trenchisolation (STI) features; and epitaxy growing or recessing the STIfeatures to form fin-like active regions. In some embodiments, one ormore gate electrodes are formed on the substrate. Some embodimentsinclude forming gate spacers, doped source/drain regions, contacts forgate/source/drain features, etc. In other embodiments, a target patternis formed as metal lines in a multilayer interconnection structure. Forexample, the metal lines may be formed in an inter-layer dielectric(ILD) layer of the substrate, which has been etched to form a pluralityof trenches. The trenches may be filled with a conductive material, suchas a metal; and the conductive material may be polished using a processsuch as chemical mechanical planarization (CMP) to expose the patternedILD layer, thereby forming the metal lines in the ILD layer. The aboveare non-limiting examples of devices/structures that can be made and/orimproved using the method described herein.

In some embodiments, active components such diodes, field-effecttransistors (FETs), metal-oxide semiconductor field effect transistors(MOSFET), complementary metal-oxide semiconductor (CMOS) transistors,bipolar transistors, high voltage transistors, high frequencytransistors, FinFETs, other three-dimensional (3D) FETs, other memorycells, and combinations thereof are formed, according to embodiments ofthe disclosure.

The novel doping techniques and semiconductor manufacturing methodsaccording to the present disclosure provide higher semiconductor devicefeature density with reduced defects in a higher efficiency process thanconventional methods. The novel techniques and methods reduce LWR toless than 5.0 nm, and reduce the exposure dose of the photoresist toless than 70 mj in some embodiments. The improvement in LWR and criticaldimension uniformity (CDU) is greater than 3% in embodiments of thedisclosure over conventional manufacturing methods. In some embodiments,the exposure dose is reduced by greater than 3% over conventionalmanufacturing methods. The defect rate is reduced by greater than 5%over conventional manufacturing methods in embodiments of thedisclosure.

An embodiment of the disclosure is a method of manufacturing asemiconductor device including forming a dopant layer including a dopantcomposition over a substrate. A resist layer including a resistcomposition is formed over the dopant layer. A dopant is diffused fromthe dopant composition in the dopant layer into the resist layer; and apattern is formed in the resist layer. In an embodiment, the diffusing adopant includes heating the dopant layer and the resist layer at atemperature ranging from 40° C. to 250° C. In an embodiment, the forminga dopant layer includes applying a dopant composition including a dopantand a solvent over the substrate. In an embodiment, the forming a resistlayer includes a chemical vapor deposition, a physical vapor deposition,or an atomic layer deposition operation. In an embodiment, the dopantcomposition includes one or more of a photoacid generator, a quencher, aphotobase generator, an organic acid, an inorganic acid, an organicbase, an inorganic base, a crosslinker, a surfactant, a solvent having aboiling point greater than 100° C., water, or a chelate. In anembodiment, the method includes heating the dopant layer at atemperature ranging from 80° C. to 250° C. before forming the resistlayer. In an embodiment, the resist composition includes anorganometallic compound.

Another embodiment of the disclosure is a method of manufacturing asemiconductor device including forming a metallic resist layer includinga metallic resist composition over a substrate. A dopant layer includinga dopant composition is formed over the metallic resist layer. A dopantis diffused from the dopant layer into the metallic resist layer, and apattern is formed in the metallic resist layer. In an embodiment, thediffusing a dopant includes heating the dopant layer and the metallicresist layer at a temperature ranging from 40° C. to 250° C. In anembodiment, the dopant layer is formed in a vacuum chamber at a pressureless than atmospheric pressure. In an embodiment, the dopant compositionincludes one or more of a photoacid generator, a quencher, a photobasegenerator, an organic acid, an inorganic acid, an organic base, aninorganic base, a crosslinker, a surfactant, a solvent having a boilingpoint greater than 100° C., water, or a chelate. In an embodiment, thedopant layer is formed in a vacuum chamber at a pressure less thanatmospheric pressure. In an embodiment, the method includes heating thedopant layer at a temperature ranging from 80° C. to 250° C. In anembodiment, the metallic resist composition includes an organometalliccompound.

Another embodiment of the disclosure is a method of manufacturing asemiconductor device including forming a dopant layer including a dopantcomposition over a substrate. A photoresist layer is formed by a vaporphase deposition technique over the substrate. A dopant is transferredfrom the dopant layer into the photoresist layer. The photoresist layeris selectively exposed to actinic radiation to form a latent pattern inthe photoresist layer, and the selectively exposed photoresist layer isdeveloped to form a pattern in the photoresist layer. In an embodiment,the dopant layer is formed by a vapor phase deposition technique. In anembodiment, the transferring a dopant from the dopant layer into thephotoresist layer includes heating the dopant layer and the photoresistlayer at a temperature ranging from 40° C. to 250° C. In an embodiment,the vapor deposition technique is selected from the group consisting ofchemical vapor deposition, physical vapor deposition, and atomic layerdeposition. In an embodiment, the dopant composition includes one ormore of a photoacid generator, a quencher, a photobase generator, anorganic acid, an inorganic acid, an organic base, an inorganic base, acrosslinker, a surfactant, a solvent having a boiling point greater than100° C., water, or a chelate. In an embodiment, the actinic radiation isextreme ultraviolet radiation or an electron beam.

The foregoing outlines features of several embodiments or examples sothat those skilled in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodiments orexamples introduced herein. Those skilled in the art should also realizethat such equivalent constructions do not depart from the spirit andscope of the present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A method of manufacturing a semiconductor device,comprising: forming a dopant layer comprising a dopant composition overa substrate; forming a resist layer comprising a resist composition overthe dopant layer; diffusing a dopant from the dopant composition in thedopant layer into the resist layer; and forming a pattern in the resistlayer.
 2. The method according to claim 1, wherein the diffusing adopant comprises heating the dopant layer and the resist layer at atemperature ranging from 40° C. to 250° C.
 3. The method according toclaim 1, wherein the forming a dopant layer comprises applying a dopantcomposition comprising a dopant and a solvent over the substrate.
 4. Themethod according to claim 1, wherein the forming a resist layercomprises a chemical vapor deposition, physical vapor deposition, oratomic layer deposition operation.
 5. The method according to claim 1,wherein the dopant composition comprises one or more of a photoacidgenerator, a quencher, a photobase generator, an organic acid, aninorganic acid, an organic base, an inorganic base, a crosslinker, asurfactant, a solvent having a boiling point greater than 100° C.,water, or a chelate.
 6. The method according to claim 1, furthercomprising heating the dopant layer at a temperature ranging from 80° C.to 250° C. before forming the resist layer.
 7. The method according toclaim 1, wherein the resist composition comprises an organometalliccompound.
 8. A method of manufacturing a semiconductor device,comprising: forming a metallic resist layer comprising a metallic resistcomposition over a substrate; forming a dopant layer comprising a dopantcomposition over the metallic resist layer; diffusing a dopant from thedopant layer into the metallic resist layer; and forming a pattern inthe metallic resist layer.
 9. The method according to claim 8, whereinthe diffusing a dopant comprises heating the dopant layer and themetallic resist layer at a temperature ranging from 40° C. to 250° C.10. The method according to claim 8, wherein the dopant layer is formedin a vacuum chamber at a pressure less than atmospheric pressure. 11.The method according to claim 8, wherein the dopant compositioncomprises one or more of a photoacid generator, a quencher, a photobasegenerator, an organic acid, an inorganic acid, an organic base, aninorganic base, a crosslinker, a surfactant, a solvent having a boilingpoint greater than 100° C., water, or a chelate.
 12. (canceled)
 13. Themethod according to claim 8, further comprising heating the dopant layerat a temperature ranging from 80° C. to 250° C.
 14. The method accordingto claim 8, wherein the metallic resist composition comprises anorganometallic compound.
 15. A method of manufacturing a semiconductordevice, comprising: forming a dopant layer comprising a dopantcomposition over a substrate; forming a photoresist layer by a vaporphase deposition technique over the substrate; transferring a dopantfrom the dopant layer into the photoresist layer; selectively exposingthe photoresist layer to actinic radiation to form a latent pattern inthe photoresist layer; and developing the selectively exposedphotoresist layer to form a pattern in the photoresist layer.
 16. Themethod according to claim 15, wherein the dopant layer is formed by avapor phase deposition technique.
 17. The method according to claim 15,wherein the transferring a dopant from the dopant layer into thephotoresist layer comprises heating the dopant layer and the photoresistlayer at a temperature ranging from 40° C. to 250° C.
 18. The methodaccording to claim 15, wherein the vapor deposition technique isselected from the group consisting of chemical vapor deposition,physical vapor deposition, and atomic layer deposition.
 19. The methodaccording to claim 15, wherein the dopant composition comprises one ormore of a photoacid generator, a quencher, a photobase generator, anorganic acid, an inorganic acid, an organic base, an inorganic base, acrosslinker, a surfactant, a solvent having a boiling point greater than100° C., water, or a chelate.
 20. The method according to claim 15,wherein the actinic radiation is extreme ultraviolet radiation or anelectron beam.
 21. The method according to claim 8, wherein the forminga dopant layer comprises: forming a mixture of a photoacid generator ora photobase generator and a solvent; and applying the mixture over themetallic resist layer.